Field of the Invention
This invention relates to methods of manufacturing low cost, high frequency semiconductor packages having very low parasitic inductance to the header.
2. Description of the Prior Art:
High frequency semiconductor packages are used for holding high frequency semiconductor components, such as microwave transistors and the like, and for providing readily available terminals for connection to other components. For such packages it is important to reduce parasitic coupling between terminals, which parasitic coupling degrades performance.
A variety of high frequency semiconductor packages utilized in the past have suffered from a variety of shortcomings including the necessity of providing wire bonding connections from the semiconductor component to lead terminals at different heights, being formed of a large number of conductive and insulative members bonded together, requiring expensive precision components such as apertured beryllia insulators, and requiring expensive apparatus for the manufacture of the packages. A high frequency semiconductor package having a structure which provides excellent high frequency performance and yet requires a small number of parts in the construction thereof is described in pending U.S. patent application, Ser. No. 303,466 now U.S. Pat. No. 3,784,884 assigned to the assignee of the present invention. The structure described herein requires coined bonding rails extending from the header in one embodiment thereof, requiring expensive coining apparatus and also requiring the use of an expensive material such as silver for the header. Further, design modifications for the prior art high frequency semiconductor packages to accommodate larger semiconductor chips, usually require extensive redesign of most of the package parts and fabrication apparatus, thereby making design modifications expensive.
The present invention solves many of the above-mentioned shortcomings of the prior art by providing a very low cost method of manufacturing a high frequency semiconductor package wherein low cost parts are assembled utilizing inexpensive apparatus, and wherein design changes affect a reduced number of the parts of the package.